I've been playing Madden for years, and what I learned is playing the computer most of the time, along with playing League games WILL improve your skills. Back on my first Madden, I couldn't score a TD for my LIFE. Or stop one for that matter. Now I supposedly have the best Defense some people have seen, I've been told. NEVER allow more than 17 points online, usually pick you off. It's cause I get to watch the best Defensive Coordinator in Football for 16 games a year. I'm a Defensive Guru =D, Come with 10+ different extremely effective looks a game.
HOWEVER.. I can't play offense as well. I play sim though, so lots of people respect me when I lose 13-7 or 17-3 because my O isn't great. Then again the majority of the time I play games with this cool guy whose been playing Madden since the first one. Hhahaha.
Just do what I said bro. It'll come to you.